Spectrum Computing

Alcoholics Anonymous wrote: ↑Sat Jun 15, 2019 5:45 pmThere is no update because nothing has changed

The change is the fact it wont be shipping by end of Q2 as promised, regardless of the issues that is an update in itself, and one that would take 5 mins to write and post. Not all backers are following every post made and I suspect many are still thinking it's going to ship in the next week or two.

Well, latest update is here and the new membranes failed so it looks like they're going with a brute force and maybe inelegant but 'foolproof' solution by just adding a couple of extra signals to the membrane, which currently look like they need to be hand soldered onto the board. Not great, not terrible? Anyway, looks like we may finally be getting our machines, so rejoice?

Godammit Doug - you know the rules.

Bizzley has to be the first for bitching when the updates come out!

The board has a 2-tail connector socket. The hand-soldering is just awkward wording. It refers to the socket being fitted at SMS by hand in rework stations, as the assembly line board manufacture has already happened a long time ago.

At last, sense has prevailed.

Then when it's done if there's still a problem the team will have to accept the problem was elsewhere all along. We've all been there!

namco wrote: ↑Sun Jun 23, 2019 7:21 pm Godammit Doug - you know the rules.

Bizzley has to be the first for bitching when the updates come out!

I didn't mean to sound like I was bitching, I'm really pleased about the news and glad to see common sense has prevailed.

However, I'd be lying if I said my comment wasn't tempered to being less than positive to pander to the moaners

Ahh, good. I was never keen on the purely mechanical approach, as I said earlier in this thread...

1024MAK wrote: ↑Mon May 13, 2019 3:26 pm The problem has been and always will be that a purely mechanical membrane keyboard system is never good at making two independent switch contacts at the same time. Even during the days of Sinclair. Far too often on my ZX Spectrum+ keyboards, I get the wrong action unless I press the key squarely.

The better solution would have been to do what Amstrad did with the +2A/+2B/+3/+3B and have a normal two layer membrane and perform the additional switching in a gate array (CPLD or FPGA) chip.

Let’s hope they can get the new membrane produced quickly and without any further hiccups.

Mark

Ok, time for a silly (or maybe not) question

Would anybody by able to explain in layman terms what's the deal with the keyboard here?

I believe keyboard manufacturing isn't a rocket science, especially in 2019. Chinese make hundreds of millions of PC keyboards
each year for a really little money. Plus consoles, plus calculators and so on. I'm currently typing on such a cheap keyboard and it
never failed me, it just works.

Why is the Next team struggling with the keyboard for almost 2 years? Don't we have a ready, working solutions how to make a keyboard?

Ralf wrote: ↑Mon Jun 24, 2019 8:12 pm Why is the Next team struggling with the keyboard for almost 2 years? Don't we have a ready, working solutions how to make a keyboard?

My personal guess is that they went quite far down the original +/128k look route, which in and of itself informs the mechanical design, but also wanted to improve the 'feel' of it therefore making a rod for their own backs in terms of a custom design. I don't really know. Also I was a rubber key and +2 only owner and have never used the +/128k keyboards so never had a horse in the race in terms of feel, and the first thing I'll do is hook up an external anyway to keep it in the best condition I can!

Having said that I do appreciate the teams effort to make it the best they could, but having some experience of electronic design/manufacture I'm a little embarrassed for them the 'will deffo work' solution is the addition of a couple of signal traces, when the delay has been as long as it has.

But, probably a lot of info I'm not privy to, so all hearsay and conjecture. I'm just really looking forward to getting mine now and after all the delay getting quite excited, when I put my pledge in I accepted there and then I might lose the money.

Ralf wrote: ↑Mon Jun 24, 2019 8:12 pm Would anybody by able to explain in layman terms what's the deal with the keyboard here?

It’s not a silly question.

The problem goes back to the original design of the rubber key model. The design only allowed for a maximum of 40 individual keys (not including duplicates). The original uses a 5 by 8 matrix (hence 5 x 8 = 40). If you want a modern ‘PC’ keyboard version of this, yes it is dead simple. However, I continue with the story...

So when Sinclair wanted to add extra keys as part of the ZX Spectrum+ design, they had to come up with a cunning plan. There were four obvious possibilities:

• Redesign the keyboard, the PCB and the ULA so that a bigger matrix could be used (more matrix lines means more keys) - rejected presumably due to cost and compatibility.
• Find a supplier that could provide proper keyboard keys including some with two sets of contacts (so that with the extra keys, they could operate and pretend to be two separate keys from an electrical point of view - same as the user pressing two keys at the same time) - again, rejected presumably due to cost.
• Keep the ULA as per the existing 16K/48K rubber key models, but modify the PCB to have extra circuitry to handle a bigger keyboard matrix and use a membrane with two conductive layers like in the rubber key model, but with more keys.
• Keep the existing PCB and ULA design and instead use effectively two membranes on top of one another. So that for the extra keys, when you press them, contacts on each of the membrane layers “make contact”. Hence one physical key can operate two separate circuits and hence electrically have the same effect as the user pressing two keys at the same time. There are ‘rubber’ domes between the membrane and the hard plastic key tops rather than metal springs. This was the cheapest so that’s what they went for, despite the poor feel of the keyboard.

Why was it a requirement to electrically operate two keys at the same time? Well that’s because most of the extra keys are performing the same function as that when the user on the rubber key has to press two keys at the same time. For example to delete a character, on the rubber key you push and hold CAPS SHIFT then press the 0 (zero) key. On the plus, the delete key closes contacts that make the ROM code think that both the CAPS SHIFT key AND the 0 (zero) key have both been pressed at the same time, hence the action is to delete a character.

One of the promises with the Next, is that of a better keyboard. The thinking was that for the extra keys, one physical key could operate two sets of membrane contacts at the same time, but only using a normal layer membrane.

But alas, the reliability of both these contacts making at the same time is poor and very dependent on the angle that the key is pressed. Hence various different designs being tried to no avail.

The solution is to abandon this daft idea of trying to reliably simultaneously operate two physical contacts at the same time. And instead add extra keyboard matrix lines. Then in the circuitry, have some logic to do the conversation.

This method, is, in my humble opinion what they should have done in the first place.

Note that modern PC keyboards are membrane types, but they have a very large matrix, and have a special microcontroller chip to scan the matrix and work out which key or keys are being pressed. They then send a signal to the computer with the details.
But in a ZX Spectrum, the Z80 microprocessor under the control of software (the ROM) does the scanning of the matrix. So from the point of view of the Z80 and the software, the signals from the keyboard have to look like it is a rubber key 5 x 8, 40 key keyboard in order to maintain compatibility...

Mark

Thanks for the great explanation. I believe nowhere else I would find it exaplained with such details. And yes, it's simple and I understand it

So Sinclair used a hacky solution when going from Zx Spectrum to Zx Spectrum + to save costs.

And 35 years later, the Next team instead of doing everything in the standard, "kosher" way, tried to copy this hack but improve it at the same time.

And went into a blind alley. And required time to grow up to scrap their work and start again in another way.

Sometimes you are too close to a project to see the way through.

*Tumbleweed blows past*

ZX Next Kickstarter Update #49, first really good news in a long time but we're all studiously ignoring it?

*lone cricket*

2hr later edit: Just seems a bit odd is all. I'm quite pleased by the news, maybe others feel they have heard it all before. I don't know, but on the first good news in a long time, I would have thought (hoped even) some fireworks would be allowed.

There's news?

ZxSpence wrote: ↑Thu Jul 18, 2019 7:39 pmThere's news?

You replied while I was updating the previous post..

Yes, update #49 went out from Henrique about 8am UK today, via the Kickstarter backer emails. Keyboard all OK now, production starting as soon as next week I think?

There's more on the email, but the crux of it is here:

"Happy news: the new keyboard, already tested at the manufacturing partner, is on its way to the Next team in the UK for a final ‘I’ve tested it myself’ confirmation before the greenlight for mass production, which should happen as soon as next week. The new keyboard, based on an extended matrix as explained in the previous update, already proved a 100% accurate on the composite keys that were giving us so much grief, closing this much long-winded chapter of the project.

With this last step out of the way, we’re now ramping up for the full production of the keyboard and case, then shipping all of it to Nottingham for final assembly and posting to the backers. There’s light at the end of the tunnel at last!"

Worth opening the mailbox then.

DouglasReynholm wrote: ↑Thu Jul 18, 2019 6:47 pm *Tumbleweed blows past*

ZX Next Kickstarter Update #49, first really good news in a long time but we're all studiously ignoring it?

*lone cricket*

2hr later edit: Just seems a bit odd is all. I'm quite pleased by the news, maybe others feel they have heard it all before. I don't know, but on the first good news in a long time, I would have thought (hoped even) some fireworks would be allowed.

I got the e:mail and it pleased me to read that manufacturing should get the green light next week, I felt I shouldn’t get too excited about this. I mean I have been reading about all the setbacks until now and not letting them get me too down. So felt I should stick with that, just keep an eye on progress and leave getting exciting when I actually see the mailman coming down the path with a parcel.

Still probably 3 or 4 months out to actually getting it, first they have to make the keyboards/cases, then on the slow boat and customs...that's 5-6 weeks, then they have to assemble and test etc.

Didn't you read in the last update that there's still further pilot production testing on the keyboard, if that passes then there's pilot production testing on the case?

That's right, it wasn't there! But after over a month of silence there's been some unofficial updates stating that they actually aren't ready to start mass producing the 3000+ cases and keyboards, despite saying that in the last update, and that there's further testing stages needed. And even then that's been delayed because the guy who's doing it is on holiday.

This is rapidly becoming a joke.

And yet the fur still flies if a backer asks a pointed question on the Facebook group. Not as hostile as before after someone tore a strip off one of the worse protagonists.

Must admit I'm also disappointed, especially after my most recent cheerleading message on this exact thread. I still think it will come eventually, but I should certainly add myself to the ranks of the more sceptical now.

I can understand the delays and though it's been an annoyingly long time I'm still ok with the wait. However the lack of communication is very unprofessional and the fanbois attacking anyone who asks should imo be banned from the facebook group...if they ban detractors they should ban the toxic ones too.

It's more than reasonable for someone to ask about an update when the team has said they would give bi weekly updates and the updates would come faster now...it's been what..5 or 6 weeks since the last one? That's ridiculous, it takes 5 mins to type

"sorry guys no news yet, still waiting on xxxx, more to follow as soon as we have something"

Rather than complete silence.

Whenever anyone seems to mention that on the facebook group the fanbois start the "it'll be ready when it's done" or "I'm perfectly fine with waiting I want it done right"...which has absolutely nothing to do with the complaint about lack of updates, comprehension boys...

beanz wrote: ↑Wed Aug 28, 2019 5:54 pm Whenever anyone seems to mention that on the facebook group the fanbois start the "it'll be ready when it's done" or "I'm perfectly fine with waiting I want it done right"...which has absolutely nothing to do with the complaint about lack of updates, comprehension boys...

Well, I'm in agreement with both those quotes/ideals, but I don't think I've ever said that out loud, people's fears are valid and as such the lack of communication is bad. Henrique shouldn't have made a rod for his own back by announcing bi-weekly updates. Trouble is, now the well is poisoned and they are reluctant to say anything as the feedback gets more negative. My personal feeling is that they had the best intentions and found out about manufacturing the hard way, but we will get HW. One day.

I don't agree with either quote as being a valid response to a question. Had they been more transparent in the manner Beanz suggested and not fanned the vitriolic responses to us asking for updates by liking so many of the more hostile ones I would have been inclined to give them the benefit of the doubt.

It's the arrogance of the outriders, the contempt of some of the core team and the absolutely toxic way they've handled the growing irritation that leads me to suspect things are more problematic than they ever let on. Silence is bad news as far as what I can see.

There are exceptions, Jim flips between being helpful and liking those attacking anyone who asks a hard question. Mike has done his best but his enthusiasm has waned.

When things go wrong and the sun king who cannot be criticised goes quiet, it does not bode well. They are the only ones who can turn this around with a mea culpa and better PR strategy that involves being frank.